Early Intel on the Japanese Zero

by Rich Leonard(son of VF-3/42 pilot and
captured Zero test pilot William Leonard)

(See The Roundtable Forum,
issue #2008-06)

3 Feb 2008

I don’t know about biplanes. I do know that my father said he
remembered reading the McHugh report (Major James H. McHugh, USMC, assistant
naval attache for air in China) on the performance of the Zero while in VF-42 in
the very late summer to early fall of 1941 (“ . . . around the time we were
married . . .” which was 13 September 1941). VF-42 would have been, more or less, permanently aboard Yorktown by then
and still on the east coast. McHugh
actually forwarded to ONI two reports, one, in December 1940, was based upon
interrogation by the Chinese of a Japanese pilot and accurately described speed,
armament and rate of climb. The
second was in June 1941 and was based on information drawn on, and analysis of a
Zero that had been shot down in May.
I don’t know which report Dad read.
He did say it came from BuAer [U.S. Navy Bureau of Aeronautics] with
information from China; my bet is that it was a synthesis of what was available.

I have never been totally clear on whether it
was these McHugh reports that, about the same time, kicked off Jimmy Thach’s
VF-3 ruminations and experiments on defensive weave tactics at North Island or
whether it was, perhaps, a BuAer copy of the Chennault report that started the
process. Yes, Chennault did deliver
a report on the performance of the Zero to the Army, indeed, to General George
Marshall, probably drawing from the same sources as McHugh, on 12 December
1940—long before before the AVG [Flying Tiger] days; in fact just before any
serious discussion of an AVG got started.

There was another report filed with ONI by
Lieutenant Stephen Jurika, Jr., the last pre-war USN air attache in Japan based
on his observations in an aviation exhibition in Tokyo in January 1941 where the
Japanese, in a surprising lapse in their obsessive security, actually allowed
him to sit in the cockpit of a Zero.
Jurika reportedly copied the information from the side plate, and from
labels inside the cockpit, providing information on the plane’s engine, overall
design, metallurgy, and landing gear.
There was still another report issued by another Marine Major, Ronald
Boone, of ONI in the summer of 1941 that accurately described the Zero’s speed,
range, and climbing ability, but discounted its maneuverability.

In the days after his meeting with Chennault,
General Marshall, informed the attendees at another conference of this new
Japanese fighter over China that had, effectively, eliminated the CAF. Marshall also wrote to General Short
in Hawaii in February 1941 telling of the Zero’s armament and performance,
though also, incorrectly remarking on its self-sealing fuel tank armor
protection. Marshall had to have
obtained his information from somewhere.

And it was not just Generals chit-chatting
back and forth. There was certainly
information available, though its questionable the
question on how far it was disseminated, both in terms of organization and
distance.

I have a PDF file of the US Army FM-30-38
Identification of Japanese Aircraft that was published 10 March 1941. You can download your own copy
from a list of manuals found on the
WWII Aircraft Forum. The
March 1942 version is the fifth on the listing; the March 1941 version is sixth.

The March 1941 edition superseded an earlier
version from 25 June 1940 (imagine how paltry that missive would have been). It addresses the Zero on page 12
thusly [my notations]:

So, some close, some a little odd, e.g., “. .
. avoids use of acrobatics.” From my reading of other sources, I suspect a lot of this came from the
Chennault report, especially the 344 mph reported top speed and, again, the
“avoids use of acrobatics” part.
Against the then available aircraft of the CAF, the Zero was overwhelmingly
superior without a whole lot of effort.
Chennault, of course had been in China for quite some time, arriving in
1937. His report given Marshall dates
from his time as an advisor/trainer for the CAF and not from his later AVG days.

The entry for the Zero is the fourth aircraft
described in the manual. FM-30-38
starts with the “Type 96” which we know as the Mitsubishi Type 96, A5M “Claude”
series; then comes the “Fighter 97 Nakajima” which we know as the Nakajima Type
97, Ki-27 “Nate” series. The next
entry is “Fighter 98 Seversky (Also called Navy Model 12)”. According to the writeup, it is a
two-seat fighter apparently copied from a Seversky design. Looks more like a Tachikawa Ki-36
“Ida” observer liaison airplane to me, but the Japanese did have a couple of
Serversky types in their inventory.

Then comes the Zero as noted (but with no
photos or drawings) followed by the great phantom Japanese fighter of the early
Pacific days, noted in the manual as the “Fighter BFW Messerschmitt 109.” Looks like a 109E to me. More on this later.

Following the 109, the next two entries are
also of interest. The first refers
to an obvious fantasy, a “1940 Mitsubishi Fighter” which seems suspiciously like
someone’s vision of a Japanese P-38.
After that is a “Fighter (1941 Program) Mitsubishi” which, if you added
the scant information provided on that model to that provided for the Zero,
you’d end up with a better picture of the actual Zero.

The last two fighters noted in the manual are
the “Fighter (1941 Program) Kawasaki (still undergoing tests)” for which the
sole descriptors are “Mitsubishi air-cooled 1050-1350 hp” engine and a max speed
of 375 mph; and a “Fighter (1941 Program) Nakajima” with the only information
provided lists “2 20 mm cannon wing guns and 4 mgs” for armament, a “Mitsubishi
1050-1350 hp at 13,000 ft” engine and a max speed of 387. My suspicion is that we are looking
at some of the first references to the Kawasaki Ki-61 “Tony” (despite the
reference to an air-cooled engine) and the Nakajima Ki-43 “Oscar” (despite the
overly heavy armament).

The are no biplane fighters in this manual,
although, besides some float-plane types, there are entries for the “Dive Bomber
96” which corresponds to the real-life Aichi Type 94 D1A1 “Susie” that was a
copy of the Heinkel He 66. This type was already pretty much replaced by the Aichi Type 99 D3A
series “Val.”

Also, “Torpedo Bomber 96,” which is the
Mitsubishi Type 96 B4Y “Jean.” The
B4Y was largely replaced by the Nakajima B5N series (“Kate”) by the beginning of
the war. The carrier Hosho,
accompanying the “main Body” at Midway, carried them.

The March 1942 edition of this manual has 180
pages as opposed to the March 1941 edition’s 76.
It is also just chock-a-block full of what we would recognize now as
obvious, and sometimes silly, errors, e.g. Zeros and “Nagoya” Zeros in the Army
fighters section and not a few other spurious entries, which from a 2008
perspective, apparently arose from someone’s fevered imagination. In the Navy section there are two
different “Type 95” biplane fighters mentioned:
a Nakajima, apparently thought to be a Curtiss Hawk knockoff, and another
with no manufacturer noted and suspiciously similar to the Nakajima Type 95 that
precedes it in the manual. The
Mitsubishi Type 00, Zero, A6M series does not appear in the Navy section at all,
apparently morphing into an JAAF fighter...go figure.

My opinion is that multiple entries for
single aircraft types were the root of the identification problem that permeates
the early war reports. Pilots
variously reported encounters with “Type 0,” “Type 00,” “Mitsubishi Zero,”
“Nagoya Zero,” and just about any permutation of those terms you might be able
to create.

Here is where I get back to the Messerschmitt
109. My thesis is that the more
exposed one was to some of this intelligence, the more likely one was to make an
incorrect identification. In my
opinion (and I believe the 1942 edition of FM 30-38 only proves my point)
reliable intelligence on Japanese aircraft types was, to be kind, somewhat
lacking in the early days. At Coral
Sea, USN VF pilots from VF-2 and VF-42 were facing IJN carrier type aircraft for
the first time. IJN
nomenclature/designations were generally unknown, or at best, barely understood
and only by a very few, and, thus, one finds in the reports reference to Zeros
(Type 0), Nagoya Zeros (Type 00s), and other oddities, including Me 109s (though
for the most part Shoho’s Type 96 A5Ms were correctly identified). VF-2’s CO Paul Ramsey was even given
credit for downing a 109.

Much of the problem with identification came from intel briefings that were
somewhat less than helpful in the long run.
Me 109s are the prime example of this problem. There was, apparently, some
discussion of Japanese types at Pearl Harbor and this information was being
disseminated to squadron personnel as
late as the run-up to Midway and even beyond.
So, one finds Ramsey reporting action against Me 109s at Coral Sea and
Bert Earnest of VT-8 (Det) reported being shot up by the same at Midway. There were even reports of 109s
wandering around in the early days of the Solomons campaign. One evening in the Pensacola Officers Club, Bert Earnest gave me a wry
grin when I mentioned it and said “We were told at Pearl to expect to see 109s,
so that’s what I reported. I really
didn’t know or care, all I cared about was they were shooting at me.”

Was Ramsey the only one who saw 109s at Coral
Sea? No, he was not. For example, in an interview at
BuAer on 16 June 1942, LT Noel Gayler, in discussing the Coral Sea action
states:<

“After we ran out to the end of our navigational leg we were in very poor
weather and no sign of the Japs. So
Commander Ault, who was the Group Commander, directed the torpedo plane
commander by radio to fly a box. He
turned 90º to the left and after about two minutes on that leg came to a
comparatively large clear area.
Under the rail squalls on the far left side of the area, say 20 miles away, we
saw the Jap outfit. The first thing
we saw was the smoke of some big ship burning. She had been attacked by the Yorktown’s air group. Then you could see white wakes over
there.

“We immediately headed toward them. The Group Commander tried to get the bombers back in contact with us and
directed the torpedo planes to circle and wait for them, so the attack could be
coordinated, but without any success.
The dive bombers never did find the target, and finally had to jettison
their bombs and go home. Four dive
bombers, lead by the Group Commander, did attack with the VF.

“After about two minutes in this clear space, we were jumped by fighters from
the Jap carriers. I should say
there were probably four or five Jap fighters.
At first they were all air-cooled type Zeros or some modification—it was
the first I’d seen of them. Then,
after a minute or two of fighting, more fighters appeared on the scene that were
liquid-cooled jobs that looked very similar to the ME–109F. I can’t say definitely what they
were, but they were planes similar to them.
Those planes I never saw take any real part in the action. All I saw was them coming at us.

“The Jap fighters have excellent performance; their
rate of climb is as good as that of any plane I’ve ever seen. They can climb at an attitude that
most planes won’t climb in, and their general maneuverability is very good. They have big ailerons on the
trailing edge and are extremely maneuverable.
The Jap pilots, however, make mistakes and quite often give you a good
shot at them.> A typical attack is
for them to take the topside from you if they can and come out on your tail at
so much speed that they overrun.
That’s a typical mistake they make.
Realizing they’re in a bad spot they will pull out directly in front of you. They climb so fast that they open
the range on you as you’re shooting at them.
About the time you get well on them your Grumman will run out of flying
speed and you drop out of it. Then
they come back at you. However,
they do give you a good shot at them and if you can shoot, you should be able to
hit them. If they came down with
reasonable speed they could stay behind you and ride you all afternoon
long—there’d be nothing to it. On
the other hand, the Zero fighter is apparently not protected at all and in
addition it has very poor armament; two light machine guns and two slow firing
20 mm cannon which are not as damaging as you might think, even if they get
hits. And they don’t get hits.”

What we are working against is the reporting
of events, i.e., encounters with enemy types based on the knowledge that the
individual unit had at the time. It
has been related to me that the folks in VF-42 never heard of the possibility of
encountering Me 109s, which might explain why they never made such a report. On the other hand, VF-42 pilots’
knowledge of actual Japanese types and nomenclature was sketchy at best (even
though BuAer’s writeup of the report by the Naval Air Attache for China had
floated through the ready room during the late summer of 1941). VF-42 had been deployed on Yorktown
in the Coral Sea/Solomons area for more than 80 days at that point and perhaps
had not received the dubious benefit of the latest thinking of the intel types. On the other hand, VF-2 was freshly
deployed from it’s transition to F4Fs from F2As and had the opportunity to
partake of the intel wisdom...which spoke of various breeds of Zeros and warned
of the presence of Messerschmitt fighters.

You don’t see Me 109s being reported by VFs
at Midway. Probably because VF-3
pretty much carried the ball, VF-wise, in the battle and Thach was already up on
Japanese VF types, at least so far as to not expect to see the Me 109. The majority of his divisions and
sections were led by VF-42 veterans, and they were still untainted by the
possibility of sighting wayward 109s.
The 16 pilots from VF-42 that filled out Thach’s VF-3 went from landing
their F4F-3s at Ewa and the next day riding over to Kaneohe to report to Thach. The rest of their time was spent
getting organized and squared away in the new F4F-4s. There was no intel briefing on
Japanese aircraft before Midway for VF-3.

It was not until after Midway that
identification of aircraft types started to settle down become standardized.

Ships were a different matter altogether. While identification of actual ships
by individual pilots might be somewhat iffy, most of the information available
was pretty accurate. I have an
original 1942 Janes Fighting Ships which covers everybody rather
thoroughly. The War Department
publishication FM-30-58 “Identification of Japanese Naval Ships” dated 28
December 1941 (also downloadable from the site noted above) has most of the
basics correct. And there is always
the fairly accurate ONI 42 series that covered the Japanese Navy long before and
into the war years until replaced by the 222 series in 1944. I also have a document published at
NAS Maui, (sometime in the winter of 1942-1943) which provides a quick
description for ship types, both USN and IJN.
It runs seven pages legal size and the descriptions are just snippets,
for example, in the Japanese battleship descriptions:

I think it probably safe to say that at the
beginning of the war there was considerably more known about the ships of the
Japanese Navy than there was known about its aircraft, or for that matter the
aircraft of the JAAF.